Expats, Amazon Prime’s adaptation of Janice Y. K. Lee’s best-selling novel The Expatriates, is a slow-burn drama following the lives of three American women in Hong Kong in the aftermath of a tragedy. Each protagonist deals with complicated feelings of grief as their lives overlap, with the affluent Margaret (played by Nicole Kidman) serving as the story’s anchor. Yet in the series’ splendid fifth and latest episode, titled “Central,” Margaret doesn’t appear until nearly 40 minutes in, and the women’s troubles fade into the background. Instead, the show brings into focus the people who have been hovering around the margins of the main characters’ lives: their live-in domestic helpers, non-expat friends, the church pastor. Taking a narrative departure several hours into a TV show’s run is not a new technique. But “Central” is unusually expansive in scope as well as in structure, conveying an inverted, impressionistic take on everything viewers have seen so far. By spending significant time away from its protagonists, the show reveals truths about them that they themselves never could. I first …